They are nocturnal and sleep a lot during the day.

But they are industrious little ba$tards. Our lake had moss pretty bad and the little $hit$
collected every piece of moss from the entire lake and built up a 12' high pyramid of moss mud and sticks around the stack
so they could clog up 8 2" holes.

Almost impossible to tear apart but the lake is clean now.

My dad caught one mid day asleep under the boathouse and
dispatched it with a shotgun.

You will see them sometimes in the very early morning or
very late evening. I never have hunted them at night.

If they disappear destroy their dam it will drive them nuts
and they will get back to work.

They don't always go back to their houses either. If they can find a safe place like under a boat dock, they might sleep there.
Trying to find where they were one time I destroyed one of their houses and several just took up residence under the boat dock.
You could stomp on the boat dock middle of the day and off they would go and pop up about 70 yards away. Good target practice.

I put out traps for them sometimes, but would rather shoot them.
I prefer the sport.

Tiny target though, like 2" of head sticking out of the water
so a dialed in tight shooting rifle is a must. Best one so far for me was my savage
26" barreled 223 that would shoot 3/8" groups.

If you are going to trap them, supposedly small strips of green poplar bark will drive them crazy and they will walk right into a trap.
I have never tried that one.

There is a really good scent that will do it too, but I have yet to find out the name of the one that works best.

I caught a a few with large spring traps from sportmans guide.